O Tempora
by Neymovirne
Summary: Sent to the past in a combination of malfunctioning Vanishing Cabinet, broken Time Turner and Potter luck, Harry has to attempt to stay sane amongst many disturbing revelations that Slytherin House of his parents' days will bring.


Harry woke up to the acrid smell of ammonia and burnt socks and the sound of tuneless yet cheerful singing.

"Shut your gob, Roy! It's six in the morning, are you mental?!"

"What is this awful smell? Snape, if you're brewing in the bathroom again, Merlin help me—"

"Fuck off, Avery! It's not me, I'm trying to sleep here!"

Harry fumbled for his glassed and flicked his wand, peering from the crack that appeared in the curtains.

"Now, now, my dear friends, there's no need to shout. The smell may be a little unpleasant, but beauty has its price!" Teenage Gilderoy Lockhart pranced through the room, sporting impressive auburn perm.

"Oh no! No no no! Not the Everett's Everlasting Curls! The Prefects' bathroom still reeks of this shit even two whole weeks after Jones decided to use it for her makeover!"

"Oh pish posh, we'll just have a good airing!"

"A good airing?! We live in a fucking dungeon, you imbecile!" The curtains on the bed opposite Harry's flew open, revealing an angry boy with a hooked nose, his usually lanky black hair stuck in every direction.

With a groan, Harry buried his head into the pillow. Time travel _sucked_.

* * *

As he chewed his toast morosely, Harry kept throwing glances at the Gryffindor table where Sirius and his father were laughing at something, thick as thieves. People at his own—and did he really just called Slytherin as his own?—table were looking at him with wary curiosity, but nobody tried to approach him yet. He didn't know if the reason for that was the way Dumbledore introduced him as a time traveller yesterday morning, the fight he had with some inbred twins about the merits of certain Dark Lords and blood purity yesterday afternoon, or the stench of Lockhart's hair potion on his clothes that nothing could dispel so far.

"Henry Bond, our new... celebrity," said a female voice behind him. Harry choked on his tea, eyes involuntarily darting to Snape at the end of the table, but his future professor was picking at his plate absentmindedly, absorbed in a book.

A brown-haired girl with a ponytail flopped at the bench beside Harry, studying him with an amused and calculating look in her eyes. Something about her was vaguely familiar.

"A time traveller, huh? So how much into the future are you?"

People around them were trying to not eavesdrop too overtly, with varying success. A burly fellow who looked like Goyle shifted closer, dragging his plate with him, and was shushed by another boy at his side. Snape still appeared to be deep in his reading, but Harry could tell he was listening to every word.

"Far enough. I cannot tell you anything specific. As Dumbledore explained, even the slightest change in the future might cause a ripple effect resulting in me popping out of existence."

"Yeah, yeah, Dumbledore prattled about paradoxes long enough yesterday." The girl made a face. "It's just—" Narrowing her eyes, she gave Harry a once-over, looked in the direction of the Gryffindor table, and back at Harry again. "If you don't mind me saying, you look awfully like Potter over there."

Damn. So much for keeping a low profile. All those dire warnings, and his cover was blown in less than a day. Harry was now glad that he hadn't gone with his father's name for an alias, as he had first wanted.

Snape abandoned all pretence of reading and was now glaring at him accusingly. Harry had to think fast.

"I don't actually look like him at all."

The girl looked at him dubiously.

"It's true! Dumbledore cast a powerful glamour to conceal my appearance completely. I can hardly go around with my real face and risk changing the timeline!"

Of course, Dumbledore did no such thing. Come to think of it, the Headmaster could at least change his hair colour.

"James Potter, the model student." The girl snorted.

Harry cracked an answering smile.

"Anyway, don't know if we've met in the future," she said, expression of hungry curiosity fleeting across her face. "But my name is Margarita McFly. You can call me Rita."

Harry's eyes widened in recognition.

* * *

 _This is all Malfoy's fault!_

Scowling, Harry walked down to the dungeons from the Headmaster's office. According to Dumbledore, he would have to spend at least a month in the past while Dumbledore was figuring how to send him back (or rather forward).

 _Figures I'd find the ferret the one time I was NOT stal—looking for him!_

Harry had spent hours attempting to break into the Room of Requirement to find out what Malfoy was up to. That particular night, however, he was aimlessly roaming the corridors before stumbling—quite literally—across Mrs. Norris. The Room readily opened to hide him from Filch, and he found Malfoy fiddling with some sort of a cabinet inside. Wands were drawn, and one of the spells brought down the shelf with a broken time turner on it. So it was a combination of the Vanishing Cabinet, spilt time sand and Potter luck that brought Harry to his current situation.

The sound of the steps behind him brought Harry out his musings, but before he could react, the world turned black.

* * *

Harry woke up in a broom closet with ropes around his body. Seventh-year Narcissa Black, robes and hair immaculate as ever, watched him impassively, twiddling Harry's wand between her fingers.

"Are you really a time traveller?" she asked.

With cold dread, Harry realized he was compelled to give a positive answer.

"What is your name?"

"Harry James Potter," he said, trying and failing to stay silent.

"So you are related to Potter, after all," Narcissa drawled. "Is he your father?"

"Yes."

"And who is your mother?"

"Lily Evans."

Narcissa wrinkled her nose. "No matter. Let's get to the real question."

Harry braced himself for interrogation about Voldemort and the war. He wondered how to at least avoid Obliviation. Seeing how easily she captured him, Harry doubted his chances. If it had been Narcissa in the Department of Mysteries instead of her husband last year, Voldemort would have had the prophecy for sure.

"Will I marry Lucius Malfoy?" Narcissa asked.

 _What?!_

"Yes."

"Good." She allowed herself a little triumphant smirk.

Vanishing the ropes, she handed a bewildered Harry his wand and left the closet with a regal nod in his direction.

* * *

Lifting his head from Transfiguration homework, Harry caught Avery and Mulciber staring at him and whispering heatedly for the fourth time this evening. His patience had been wearing thin. Narcissa decided to err on the side of caution with her Veritaserum, so he had to spend an entire hour in the small dusty closet and had a raging headache.

Rita usually knew everything about everyone, but she was out somewhere "pursuing a certain self-enrichment project." Lockhart, who had put a wig on a scull on the mantelpiece and was currently practising hair styling charms, was oblivious to anyone other than his own glorious self. It seemed that Harry had only one other option.

With a sigh, he turned to the person in the chair next to him. Brow furrowed in concentration, Snape was scribbling something in what appeared to be their sixth-year Potions textbook. Harry narrowed his eyes at it, suspicion forming in his mind. For now, however, he had other concerns.

"Oi, Snape!"

"What?"

"Do you know what their problem is? Mulciber and Avery's?" Harry asked in a low voice.

Snape snorted.

"Both of them think that your time travel story is too farfetched, especially after your performance in Defence today, and you are most likely here be a spy in the Slytherin common room. Mulciber is sure that Dumbledore sent you."

"That's ridiculous! And I'm not that good at Defence," Harry protested. He knew he needed to up his game, especially after the Narcissa incident. "It's just our professor is likely to snuff it if somebody so much as coughs in his direction. He must be at least two hundred years old!"

"Two hundred and thirteen, actually. At least Professor Featherwright isn't likely to elope with a fourth-year as the previous one did."

"A fourth-year?!" Apparently, the standards for the Defence position were slipping since the 70s already.

Snape nodded.

Harry decided to get the conversation back on track. "So Mulciber thinks I'm spying for Dumbledore. What about Avery?"

"Avery thinks you're spying for—" Snape glanced around, then at Harry's left hand, "—for other people."

It took a moment for the meaning to register. When it did, Harry's mouth fell open.

"You're kidding me! How stupid is he? I've thought I made my opinion on the topic clear the very first day I came here."

"Yes, that was very Gryffindorish performance." Snape curled his lip with distaste. "Some might say too Gryffindorish. Avery thinks that it would be a perfect cover to gauge people's true loyalties."

"Or get myself beaten up." Harry snorted, still in disbelieve.

"Or that," Snape agreed noncommittally, but his black eyes bore into Harry with the intensity that reminded him of their future Legilimency lessons.

"You don't really believe that nonsense yourself, do you?"

"Do you take me for an idiot?"

Harry relaxed a little.

"Still, you've got my reference, and not many people are privy to that… piece of information." Snape's eyes darted to Harry's forearm again.

"Well, I _am_ from the future, and it's rather common knowledge then!"

"See? You can explain any slip-up that way. This is why time travel would be a perfect cover!" Snape crowed.

"Okay, fine." This was getting ridiculous. "So if I were a spy, which, for the record, I am not, who do _you_ think I'm spying for?"

Snape inclined his head to the side, studying Harry as if he was a particularly interesting (and nasty) potion ingredient.

"What I think—" He paused and then looked at something over Harry's shoulder. "Oh look, is that Regulus Black being chased by a merman?"

Rolling his eyes, Harry turned around. He just hoped that adult Snape was better than that when dodging questions from Voldemort, or they were all truly screwed.

He guessed he should not have been that surprised to see Regulus Black waving at them from the murky waters behind the common room windows.

* * *

Teeth clattering, Regulus Black sat in the pile of blankets in front of the fire.

"What in Merlin's name possessed you to go diving in Great Lake in the middle of February?" Narcissa Black threw her hands in the air, a gesture only she could make so dignified.

"I had to do something to make Barty notice me finally! He is so smart, doing all these OWLs. He's been doing a Herbology project about that Gaukos plant, so I thought I'd get it for him for Valentine's Day," he babbled. "It was perfectly safe, I promise you, Cissy, I got enough gillyweed and everything!"

"Yes, getting chased by grindylows and angry mermen with tridents is perfectly safe!" Narcissa's voice was dripping with sarcasm. The entire common room witnessed the chase, cheering and placing bets.

"Well, I really didn't expect _that_ ," Regulus said sheepishly.

"Even Sirius wouldn't be so foolish to pull a stunt like that!"

He looked at her dubiously.

"Well, yes, it's exactly the kind of idiotic stunt your brother would pull! Which brings us to the question at hand again." Narcissa's voice grew louder, "What were you thinking with this Gryffindorish—" she spat that word, "—behaviour?!"

"It wasn't Gryffindorish! I had to find a gift worthy of my soulmate!"

"A soulmate."

He raised his chin.

"Funny, I seem to recall you telling me that Gideon Prewett was your soulmate." One of Narcissa's perfectly-shaped eyebrows crept up.

Regulus flushed. "It was last year and it was Fabian! I was young and foolish. Since then, I realized that he cannot be my soulmate. He is a Gryffindor and has already graduated anyway."

"Regulus. Reggie. Little cousin," Narcissa said with a long-suffering sigh, "There. Is. No. Such. Thing. As a soulmate! This nonsense only exists in lowbrow romance novels for someone like your Prewett's sister to read."

"This is not true!" Regulus exclaimed. "And I'll prove that to you! I've seen a book somewhere on them in our library at home. I'll get it if you don't believe me!"

With that, Regulus sprang to his feet and left for the fifth year dorm. Narcissa watched him go with a dubious expression. Having been to Grimmauld Place's library, Harry couldn't help but share her doubts.

* * *

Valentine's Day came with a flurry of owls to Lockhart who had spent the night before writing love letters to himself and failing to use the handwriting-changing charm correctly. After the second time Lockhart set his curtains on fire, Harry was ready for some lethal measures, however disapproving Dumbledore might be.

Lockhart was soaking in all the stares and attention he received, alone in the middle of the table. All the other Slytherins hastily moved away from the onslaught of angry birds that didn't much care for the idea of delivering letters to their sender.

"Do you know that the group of owls is called a parliament?" asked Rita. She knew a lot of random facts like that.

"Now that sounds like Wizengamot alright," said Harry, wincing at screeches and hoots of the owls, each trying to give its letter first.

Rita snorted.

Opposite them, Severus Snape was viciously stabbing his sausage, alternating his glares at Lockhart and at the Gryffindor table. When an owl feather landed in his plate, Snape exploded.

"If you don't get rid of these owls this instant, Roy, I will hex you with the Baldness Curse. The irreversible one!"

"I know you are envious, Severus, but there's no need to be so grumpy," Lockhart pouted.

"Envious of what exactly? You've sent all these cards to yourself! That box of chocolates with an ink stain over there, you bought it at Honeydukes two months ago. You keep your hairpins there!"

Lockhart looked hurt, his usually cheerful expression dimming.

"At least I know how to use hairpins so my hair always looks fabulous! If you've had put even a little bit of care in your appearance, maybe you could have gotten that Gryffindor girlfriend of yours back. She's going to get together with your archenemy any day now!"

"Ouch," Rita muttered.

There was a pin drop silence. For a moment, Snape looked absolutely murderous, then he threw the fork he was holding with force and left the Great Hall in a fit of rage.

Harry turned to Rita in disbelief.

"Snape had a Gryffindor girlfriend?"

"I'm not sure about girlfriend exactly, but he used to be friends with Evans, that redhead witch talking to Lupin over there, until a certain incident at the end of the last year. I think they grew up together or something."

Harry gaped.

* * *

Huffing in frustration, Regulus Black closed an old tome bound in suspiciously looking leather. Harry, who was sitting in the opposite chair, looked at him questioningly.

"I should have guessed this would be the sort of thing I get from our family library," Regulus complained, showing the cover that said _Magicks of Soul_. "Detailed instructions on how to split your soul and put a piece of it in an inanimate object to achieve immortality, but nothing, nothing at all about soulmates! What a waste of time!"

That sounded disturbingly familiar.

"Hey Regulus, mind if I borrow it for a bit?" Harry asked.

"Be my guest, just don't dog-ear pages, or Mother will have my head on the wall together with the house-elves'."

Harry immersed himself in a book which turned out to be a 19th-century translation of the works of Herpo the Foul. The pictures made Harry sick, but not as sick as the thought of his mother and Snape.

At least now Harry knew exactly what Voldemort did to himself, if that counted as a silver lining.

* * *

James Potter blocked Harry's path after Charms, glaring daggers. Sirius, Remus and Pettigrew loomed behind.

"I don't appreciate a bloody snake wearing a cheap knockoff of my face," James said through his teeth.

"Too bad," Harry shrugged, "You can voice your concerns to Dumbledore; he was the one who cast the glamour." He'd be damned if he was going to let anyone here intimidate him, even if it was his late father.

"We'll be watching you, Bond. Watching you very closely," It was Sirius who said that before the group turned and stalked dramatically.

To Harry's surprise, Wormtail lingered behind. Harry usually avoided even looking at the rat, or the urge to hex him became overwhelming.

"I know you're lying," Pettigrew whispered.

Harry grew very still.

"Everybody's bought into this rubbish about the time travel, but not me," Pettigrew continued with a gleeful smile.

"Oh?"

"You are here to spy on the students!"

"And pray tell who I'm spying for then," Harry asked.

"Oh please, this is obvious!"

With that, Pettigrew turned and scampered after the other Marauders.

Harry put his head in his hands, not knowing whether to launch or to cry. Suddenly, a horrible realization came to him.

 _The Marauder's Map._

* * *

Operation "Steal the Map" was scheduled for the same evening. Harry wished he had his own Map with him when he time travelled, but at least he had his Invisibility Cloak. He just hoped it would not spontaneously merge with its old version when in close proximity or something.

Harry spent almost an hour at the entrance to the Gryffindor tower, but in the end, was able to sneak there unnoticed. Finding a place to seat safely in the overcrowded common room was a much harder task. As he couldn't risk the chair lest somebody sat on him, Harry had to sit invisible on the floor in the farthest corner. Something about that gave him Dursleys flashbacks.

The cheerful bustle of the Gryffindor common room made him feel homesick. What wouldn't he give to be in his favourite chair near the fire, playing chess with Ron and listening to him bicker with Hermione over homework.

He didn't know whether to be relieved or disappointed that neither the Marauders nor his mother were there. Watching them was a bittersweet experience.

Finally, the last person, a harassed seventh year with a stack of books, left, and Harry stood up. Before he could make more than a couple of steps though, Remus Lupin came down to the common room from the dorms. He had a familiar-looking parchment in his hands.

"I know you are here, Henry Bond," Remus said in his general direction. "Or should I say… Harry Potter?"

Harry swore under his breath and took off the cloak.

Remus looked at it curiously. "Is it James's cloak?"

"No. Well, yes, but it's a version of it from my time," Harry said as there was no point to lie.

"So the time travel is true."

He groaned. "Don't tell me you also believed the spy theory, Moony."

Remus's eyes widened at the nickname.

"There are bets, you know. But no, it sounds too ridiculous, or not enough, I suppose. You are not even glamoured, are you?"

"Nope, it's all me," Harry grinned.

"And Jim is your old man, right? Then who is your mum? Oh, don't tell me, don't tell!" Remus studied his face, bouncing on his feet excitedly. Harry stifled a giggle, remembering the usually reserved man from his own time.

"Green eyes… Oh my, Prongs is going to get the girl in the end, isn't he?"

Harry winked at him, but then sobered.

"You can't tell anyone about me, especially not him. As much as it's tempting, Dumbledore and Herm… my friend gave enough dire warnings about paradoxes to not even think about it."

"Well, we wouldn't want to erase you out of existence, would we?" Remus smirked. "So, why are you here today?"

Harry pointed at the Map sheepishly.

"Oh, you would know about that too, huh? Well, I can't give it to you, but I can keep it out of the boys' reach, at least for now. Do you know how long you're going to stay here?"

Harry scowled. "I hope Dumbledore will fix the situation soon. I really have to get to my own time."

They chatted some more, and when Harry finally returned to the dungeons, it was well after midnight. He went to bed in good spirits, hoping that the Hogsmeade visit tomorrow would cheer him even more.

* * *

The Hogsmeade visit did nothing to cheer Harry. With a nasty smirk, Filch refused to let him through the gates since he didn't have his permission slip signed.

Harry desperately wanted to get up in the air, but Scottish weather in February wasn't very favourable to flying without his Quidditch gear. After some aimless roaming around the castle, he returned to the dorm.

The dorm was filled with noxious fumes and echoey guitar riffs. Snape was stirring the cauldron mounted right in the middle of the room and humming along to a rich male voice singing phlegmatically about a killer on the road.

Well, Harry supposed he couldn't seriously expect Snape to listen to Celestina Warbeck.

Finally, Snape noticed him and scowled.

"What are you doing here? Aren't you supposed to be in Hogsmeade?"

"Aren't you? Why are you brewing here anyway?" He knew that Snape usually brewed in a disused classroom behind the portrait of Paracelsus, supplying Slytherin black market with Calming Draughts and Wit-Sharpening Solutions.

Spots of pink appeared on Snape's pale cheeks.

"This is a very exact formula that requires my undivided attention. Now make yourself scarce or I'll put you to good use chopping those slugs over there!" There they were, glimpses of his future Professor in all his irascible glory.

Harry's curiosity peaked. He looked at the perfectly prepared ingredients spread out on the board on Avery's bed. That couldn't possibly be comfortable. He narrowed his eyes at the leathery leaves Snape was adding to the potion.

"Hey, that's a lot of hellebore. Isn't it toxic?" Potions weren't his best subject, but he did get an E on his OWLs and learned a lot from the Half-Blood Prince's Advanced Potions textbook. And considering his recent suspicions about the Half-Blood Prince's identity… "It is! It is also highly hallucinogenic!" That particular property was underlined twice and marked with three exclamation points in his book.

Snape pursed his lips, "Just a little experiment in the name of research. I'm not going to ingest it."

By now, Harry was much better in deciphering what Snape was _really_ saying.

"But somebody else will, right? What exactly does this potion do?"

"Imitates the effects of LSD, muggle hallucinogenic drug," Snape said after a moment when he realized Harry wasn't going to drop the subject.

Suddenly the potion bubbled and released a cloud of thick greenish fumes.

"Was it supposed to do that?"

Snape swore and conjured a bubble-head charm, adding some liquid to the cauldron with a dropper. Between drops, he thrust a board with horned slugs at Harry and gestured to start chopping. Harry sighed. Some things never changed.

* * *

After they had decanted the potion, Snape raided Mulciber's trunk and fished out a pack of cigarettes.

"I'm not stupid enough to do experimental acid myself, in the middle of the term at least, but life is a miserable enough affair to endure it without _some_ kind of poison," he proclaimed, offering one.

As Harry finally got his coughing under control and was lying on his bed listening to the wailing guitars of Led Zeppelin on Snape's enchanted record player, he felt that all in all, life was surprisingly not that bad.

When he voiced this opinion out loud though, Snape only threw him a disgusted look.


End file.
